使用cookie紀錄訪問次數

由於是簡單的demo，我就沒有鏈接數據庫，退出重新登陸訪問次數清零，只能靠下刷新來維持下訪問次數

把用戶名和次數初始化放進cookie

        Cookie uesrnameCookie = new Cookie("username",
                request.getParameter("username"));
        Cookie visittimesCookie = new Cookie("visitTimes", "0");
        response.addCookie(uesrnameCookie);
        response.addCookie(visittimesCookie);
        response.sendRedirect(request.getContextPath() + "/cookie.jsp");

找到“username”和“visittime”的cookie，把cookie里面的用戶名和訪問次數提取出來

Cookie[] cookies = request.getCookies();
    for (int i = 0; cookies != null && i < cookies.length; i++) {
        Cookie cookie = cookies[i];
        if ("username".equals(cookie.getName())) {
            username = cookie.getValue();
        } else if ("visitTimes".equals(cookie.getName())) {
            visitTimes = Integer.parseInt(cookie.getValue());
        }
    }

更新訪問次數

    Cookie visitTimesCookie = new Cookie("visitTimes",
            Integer.toString(++visitTimes));
    response.addCookie(visitTimesCookie);